Assessing the costs of adaptation to climate change: a review of the UNFCCC and other recent estimates

This is an evaluation of estimates of the costs of adaptation made by the United NationsFramework Convention on Climate Change (UNFCCC) in 2007 and by some preceding studies(UNFCCC, 2007; Stern, 2006; World Bank, 2006; Oxfam, 2007; UNDP, 2007). The costs havebeen used as the basis for discussion regarding the levels of investment needed for adaptation toclimate change. They have been influential in the debate concerning funding for climate changeand it is important, therefore, that such estimates of cost are as robust as possible. The purpose ofthis report is to assess these estimates and consider ways to improve them in the future.The UNFCCC report was based on a set of commissioned studies (UNFCCC backgroundpapers, 2007). These took place over a short period dictated by the timescale of the UNFCCCprocess and the need to report the results to the next Conference of the Parties, so there was notime for independent review of a draft of the report.It is important, therefore, to recall the objectives of the UNFCCC report and the caveats that theauthors ascribed to its conclusions. The study was a preliminary one of the funding, especially thepublic funding, estimated to be needed in the year 2030 to meet the challenge of climate change.It is not a study of the full cost of avoiding all damage. It does not cover some important activities,and other activities are only partially covered. The authors suggest that their estimates areprobably under-estimates and that much more study is needed.The purpose of this evaluation is to consider the relative strengths and weaknesses of theUNFCCC study, so that we can determine what next steps can be taken to improve ourunderstanding of the issue. It is not our purpose here to develop a revised set of numbers forthe funding of adaptation to climate change, because we believe this requires detailed study